Such a friction welding device is known from practice. It has a plasticizing or friction unit and a positioning and compressing unit with a feed unit for a workpiece. The feed unit has a controllable hydraulic cylinder, which is connected to an external hydraulic unit, which also supplies other users of the pressure welding device. The hydraulic unit has a large pressure storage unit, which is supplied by a motor-driven pump and from which the hydraulic medium is fed to the hydraulic cylinder via a servo valve. The servo valve is connected to a controller of the friction welding device and is used to control and regulate the feed of the cylinder.
A similar friction welding device with servo valve is known from DE 199 02 357 A1. DE 20 2004 009 909 U1 shows a friction welding machine with two cylinders for compression stroke and quick motion.
DE 20 2008 005 534 U1 discloses a pressure welding device whose plasticizing unit is designed as a melting unit with a magnetically moved arc and whose compressing unit has a controllable feed drive with a hydraulic cylinder.